Write operations to mitigate write disturb

ABSTRACT

A request to write a set of host data is received. A first plurality of write operations is performed to write a first portion of the set of host data to a first set of memory cells of the memory device arranged in a first pattern. The first set of memory cells arranged in the first pattern comprises alternating memory cells on each word line of the memory device and excludes a second set of memory cells adjacent to the first set of memory cells. A second plurality of write operations is performed to write a second portion of the set of host data to the second set of memory cells arranged in a second pattern. The second set of memory cells arranged in the second pattern comprises other alternating memory cells on each word line of the memory device adjacent to the first set of memory cells.

TECHNICAL FIELD

Embodiments of the disclosure relate generally to memory sub-systems,and more specifically, relate to performing write operations to mitigatewrite disturb in memory sub-systems.

BACKGROUND

A memory sub-system can include one or more memory devices that storedata. The memory devices can be, for example, non-volatile memorydevices and volatile memory devices. In general, a host system canutilize a memory sub-system to store data at the memory devices and toretrieve data from the memory devices.

BRIEF DESCRIPTION OF THE DRAWINGS

The disclosure will be understood more fully from the detaileddescription given below and from the accompanying drawings of variousembodiments of the disclosure. The drawings, however, should not betaken to limit the disclosure to the specific embodiments, but are forexplanation and understanding only.

FIG. 1 illustrates an example computing system that includes a memorysub-system in accordance with some embodiments of the presentdisclosure.

FIGS. 2A-2B depict an example of performing write operations in adjacentcells with a delay in response to a host request, in accordance withsome embodiments of the present disclosure.

FIGS. 3A-3B depict an example of performing write operations frommultiple host requests with a delay, in accordance with some embodimentsof the present disclosure.

FIG. 4 is a flow diagram of an example method to perform writeoperations in adjacent cells with a delay, in accordance with someembodiments of the present disclosure.

FIG. 5 is a flow diagram of performing write operations using a timecondition, in accordance with some embodiments of the presentdisclosure.

FIG. 6 is a block diagram of an example computer system in whichembodiments of the present disclosure may operate.

DETAILED DESCRIPTION

Aspects of the present disclosure are directed to performing writeoperations to mitigate write disturb in a memory sub-system. A memorysub-system can be a storage device, a memory module, or a hybrid of astorage device and memory module. Examples of storage devices and memorymodules are described below in conjunction with FIG. 1. In general, ahost system can utilize a memory sub-system that includes one or morememory components, such as memory devices that store data. The hostsystem can provide data to be stored at the memory sub-system and canrequest data to be retrieved from the memory sub-system.

The memory device can be a non-volatile memory device, which is apackage of one or more dice. The dice in the packages can be assigned toone or more channels for communicating with a memory sub-systemcontroller. The non-volatile memory devices include cells (i.e.,electronic circuits that store information), that are grouped into pagesto store bits of data. The non-volatile memory devices can includethree-dimensional cross-point (“3D cross-point”) memory devices that area cross-point array of non-volatile memory cells that can perform bitstorage based on a change of bulk resistance, in conjunction with astackable cross-gridded data access array. Another example of anon-volatile memory device is a negative- and (NAND) memory device.Other examples of non-volatile memory devices are described below inconjunction with FIG. 1.

Each of the memory devices can include one or more arrays of memorycells. Depending on the cell type, a cell can store one or more bits ofbinary information, and has various logic states that correlate to thenumber of bits being stored. The logic states can be represented bybinary values, such as “0” and “1, or combinations of such values. Forexample, a single level cell “(SLC) can store one bit of information andhas two logic states.

When data is conventionally written to a memory cell of the memorydevice for storage, adjacent (e.g., contiguous, neighboring, nearby,next to, etc.) memory cells can experience what is known as “writedisturb.” Write disturb is the result of continually writing data to aparticular memory cell without writing and/or refreshing data stored atnearby memory cells, causing the nearby memory cells to change stateover time (e.g., the programmed state changes). If too many writeoperations are performed on the particular memory cell (also referred toas the “aggressor cell” hereinafter), data stored at adjacent orproximate memory cells (also referred to as the “victim cell” or “targetcell” hereinafter) of the memory device can become corrupted orincorrectly stored. The heat generated from the aggressor cell duringthe write operations can cause the memory alloy of the victim cell tocrystalize, degrading its quality. Thus, in traditional memorysub-systems, a higher error rate can result when reading the data storedat the adjacent or proximate memory cells. The higher error rate (e.g.,raw bit error rate, or RBER) can increase the use of an error detectionand correction operation (e.g., an error control operation) forsubsequent operations (e.g., read and/or write) performed on the memorycell. The increased use of the error control operation can result in areduction of the performance of the conventional memory sub-system. Asmore resources of the memory sub-system are used to perform the errorcontrol operation, fewer resources can be used to perform other readoperations or write operations. Thus, the performance of the memorysub-system can be decreased as fewer read operations and writeoperations can be performed within a particular amount of time.

To mitigate the effects of write disturb on data stored at the memorysub-system, conventional memory sub-systems typically utilize variouswrite refresh processes. For example, conventional memory sub-systemscan perform a write refresh based on a number of write operationsperformed on a managed unit. A managed unit can be defined as a unit ofuser data that is managed and/or operated on by the memory device. Amanaged unit can be defined by a size (e.g., bytes) of data. Typically,the memory sub-system stores the number of write operations performed onmanaged units of the memory device as metadata on the memory device. Thenumber of write operations performed on a managed unit can be read fromthe metadata stored at the memory device and used to determine a disturbcount for one or more of the portions (e.g., proximate memory cells) ofthe memory device. The disturb count can correspond to a number of writeoperations performed on a particular managed unit without an interveningwrite or refresh operation for the particular managed unit. Once thedisturb count exceeds a threshold number of write operations, the dataof the managed unit of the memory device can be refreshed (i.e., copiedand written to another managed unit of the same or a different memorydevice). Furthermore, some conventional memory sub-systems can utilize asingle count of write operations performed on the memory device ratherthan a separate count for each managed unit. Once the number of writeoperations satisfies a threshold condition (e.g., meets or exceeds athreshold value), a memory cell of the memory device is identified forthe refresh operation.

In some examples, refreshing the data stored at one or more memory cellscan include reading the data from the one or more memory cells, thenwriting the data back to the one or more memory cells. As the data ismore recently written back on the memory cell, the effect of writedisturb (e.g., read error resulting from state change of the cell due towrite disturb) can be mitigated as further time passes. In someexamples, refreshing the data can include clearing out the existinglogical to physical address data mapping and setting the logical tophysical address mapping anew. Since the operations involved in thewrite refresh process are performed in addition to the actual host dataoperations (e.g., read, write, etc.), the process of write refresh canreduce device lifetime and increase read time. Additionally, in across-point array type memory, the managed units of the memory devicecan be relatively small and the number of write counts can be in themillions due to high endurance of the cross-point array type memory. Thestoring of the disturb count can result in a large amount of overhead ofthe memory sub-system being dedicated towards storing the number ofwrite operations performed on managed units of the memory device.Furthermore, in a conventional memory sub-system, each time a writeoperation is performed on a particular managed unit, the metadataassociated with the number of write operations for the particularmanaged unit is read from the memory device, incremented to reflect therecently performed write operation, and then the updated metadata iswritten back to the memory device. The process of maintaining the writecount metadata is performed for each managed unit of the memory device.The performance of these operations each time a write operation isperformed consumes a large amount of resources of the memory sub-system.Furthermore, a memory device can include hundreds of thousands ofmanaged units. Maintaining the write count metadata for such a largenumber of managed units consumes a large amount of computing resourcesof the memory sub-system. This results in a decrease in the performanceof the memory sub-system as well as less capacity of the memorysub-system being used to store user data.

Aspects of the present disclosure address the above and otherdeficiencies by performing write operations to store data in particularcells to create a minimum amount of delay (e.g., lag time, wait time,etc.), without causing a delay between two consecutive write operationsto write host data, to mitigate or avoid write disturb. The minimumdelay can correspond to a threshold time based on various factors, suchas, experimentation, system specification, etc. The minimum delaybetween the write operations in adjacent cells can allow the adjacentcells to dissipate heat and reduce the temperature. As a result, thememory cells can recover before the next write operation takes place andcan be prevented from being crystalized. As the delay between writeoperations in adjacent cells increase, the RBER continues to decrease,to the point that the error rate can be completely diminished. Thepresent disclosure provides for implementing a delay in write operationsof adjacent cells by utilizing various patterns of write operations thatcause the host data to be written to memory cells that are not adjacentto each other for consecutive write operations until a sufficient delayhas occurred. For example, a first pattern can be used which can includeperforming write operations to write a set of host data to multiplecells, where a portion of the data is written to a first cell for afirst write operation, then the next cell in the array is skipped, andthe next portion of the data is written to a second cell not adjacent tothe first cell for a consecutive, next write operation. The firstpattern can continue until a time condition is satisfied. For example,the time condition can be satisfied when an elapsed time since the firstwrite operation is above a threshold time. Once the time condition issatisfied, then a second pattern can be used, where the next,consecutive write operation is performed to write the next portion ofthe host data to a cell that is adjacent to the first cell, and continueto write the remaining portions of the host data to the cells that wereskipped using the first pattern. Using the alternating patterns, thetotal time to write the host data can remain unchanged while a minimumdelay between write operations of adjacent cells is introduced bydesign. Various other patterns can be used to achieve a sufficient delaybetween two adjacent cells that minimize the effect of write disturb, asdescribed throughout the disclosure.

Advantages of the present disclosure include, but are not limited to, anincreased reliability of data stored at the memory sub-system. Since theeffects of write disturb stress on the data stored in the nearby cellsis mitigated, the number of errors found in data stored at the memorysub-system is reduced. The reduced error rate associated with the datastored at the nearby memory cells can decrease the number of errorcorrection operations that are performed by the memory sub-system andimprove the performance of the memory sub-system. Additionally, thedelay between writing to adjacent cells is implemented without anyincrease in total time performing the write operation requested by thehost system. Furthermore, by introducing an inherent delay instead ofperforming a write refresh to compensate for the effects of writedisturb, the amount of computing resources being dedicated to performingclearing and rewriting data for the write refresh is decreased. Sinceless computing resources are being dedicated to performing errorcorrection and write refresh operations, the computing resources can beused to perform other operations (e.g., reading and writing data) for ahost system and the capacity of the memory sub-system to store data fromthe host system is increased. This results in an improvement in theperformance of the memory sub-system.

FIG. 1 illustrates an example computing system 100 that includes amemory sub-system 110 in accordance with some embodiments of the presentdisclosure. The memory sub-system 110 can include media, such as one ormore volatile memory devices (e.g., memory device 140), one or morenon-volatile memory devices (e.g., memory device 130), or a combinationof such.

A memory sub-system 110 can be a storage device, a memory module, or ahybrid of a storage device and memory module. Examples of a storagedevice include a solid-state drive (SSD), a flash drive, a universalserial bus (USB) flash drive, an embedded Multi-Media Controller (eMMC)drive, a Universal Flash Storage (UFS) drive, a secure digital (SD)card, and a hard disk drive (HDD). Examples of memory modules include adual in-line memory module (DIMM), a small outline DIMM (SO-DIMM), andvarious types of non-volatile dual in-line memory module (NVDIMM).

The computing system 100 can be a computing device such as a desktopcomputer, laptop computer, network server, mobile device, a vehicle(e.g., airplane, drone, train, automobile, or other conveyance),Internet of Things (IoT) enabled device, embedded computer (e.g., oneincluded in a vehicle, industrial equipment, or a networked commercialdevice), or such computing device that includes memory and a processingdevice.

The computing system 100 can include a host system 120 that is coupledto one or more memory sub-systems 110. In some embodiments, the hostsystem 120 is coupled to different types of memory sub-system 110. FIG.1 illustrates one example of a host system 120 coupled to one memorysub-system 110. As used herein, “coupled to” or “coupled with” generallyrefers to a connection between components, which can be an indirectcommunicative connection or direct communicative connection (e.g.,without intervening components), whether wired or wireless, includingconnections such as electrical, optical, magnetic, etc.

The host system 120 can include a processor chipset and a software stackexecuted by the processor chipset. The processor chipset can include oneor more cores, one or more caches, a memory controller (e.g., NVDIMMcontroller), and a storage protocol controller (e.g., PCIe controller,SATA controller). The host system 120 uses the memory sub-system 110,for example, to write data to the memory sub-system 110 and read datafrom the memory sub-system 110.

The host system 120 can be a computing device such as a desktopcomputer, laptop computer, network server, mobile device, or suchcomputing device that includes a memory and a processing device. Thehost system 120 can be coupled to the memory sub-system 110 via aphysical host interface. Examples of a physical host interface include,but are not limited to, a serial advanced technology attachment (SATA)interface, a peripheral component interconnect express (PCIe) interface,universal serial bus (USB) interface, Fibre Channel, Serial AttachedSCSI (SAS), a double data rate (DDR) memory bus, Small Computer SystemInterface (SCSI), a dual in-line memory module (DIMM) interface (e.g.,DIMM socket interface that supports Double Data Rate (DDR)), etc. Thephysical host interface can be used to transmit data between the hostsystem 120 and the memory sub-system 110. The host system 120 canfurther utilize an NVM Express (NVMe) interface to access components(e.g., memory devices 130) when the memory sub-system 110 is coupledwith the host system 120 by the PCIe interface. The physical hostinterface can provide an interface for passing control, address, data,and other signals between the memory sub-system 110 and the host system120. FIG. 1 illustrates a memory sub-system 110 as an example. Ingeneral, the host system 120 can access multiple memory sub-systems viaa same communication connection, multiple separate communicationconnections, and/or a combination of communication connections.

The memory devices 130,140 can include any combination of the differenttypes of non-volatile memory devices and/or volatile memory devices. Thevolatile memory devices (e.g., memory device 140) can be, but are notlimited to, random access memory (RAM), such as dynamic random accessmemory (DRAM) and synchronous dynamic random access memory (SDRAM).

Some examples of non-volatile memory devices (e.g., memory device 130)include negative- and (NAND) type flash memory and write-in-placememory, such as three-dimensional cross-point (“3D cross-point”) memory.A cross-point array of non-volatile memory can perform bit storage basedon a change of bulk resistance, in conjunction with a stackablecross-gridded data access array. Additionally, in contrast to manyflash-based memories, cross-point non-volatile memory can perform awrite in-place operation, where a non-volatile memory cell can beprogrammed without the non-volatile memory cell being previously erased.NAND type flash memory includes, for example, two-dimensional NAND (2DNAND) and three-dimensional NAND (3D NAND).

Each of the memory devices 130 can include one or more arrays of memorycells. One type of memory cell, for example, single level cells (SLC)can store one bit per cell. Other types of memory cells, such asmulti-level cells (MLCs), triple level cells (TLCs), and quad-levelcells (QLCs), can store multiple bits per cell. In some embodiments,each of the memory devices 130 can include one or more arrays of memorycells such as SLCs, MLCs, TLCs, QLCs, or any combination of such. Insome embodiments, a particular memory device can include an SLC portion,and an MLC portion, a TLC portion, or a QLC portion of memory cells. Thememory cells of the memory devices 130 can be grouped as pages that canrefer to a logical unit of the memory device used to store data. Withsome types of memory (e.g., NAND), pages can be grouped to form blocks.Some types of memory, such as 3D cross-point, can group pages acrossdice and channels.

Although non-volatile memory components such as 3D cross-point array ofnon-volatile memory cells and NAND type flash memory (e.g., 2D NAND, 3DNAND) are described, the memory device 130 can be based on any othertype of non-volatile memory, such as read-only memory (ROM), phasechange memory (PCM), self-selecting memory, other chalcogenide basedmemories, ferroelectric transitor random-access memory (FeTRAM),ferroelectric random access memory (FeRAIVI), magneto random accessmemory (MRAM), Spin Transfer Torque (STT)-MRAM, conductive bridging RAM(CBRAM), resistive random access memory (RRAM), oxide based RRAM(OxRAM), negative-or (NOR) flash memory, electrically erasableprogrammable read-only memory (EEPROM).

A memory sub-system controller 115 (or controller 115 for simplicity)can communicate with the memory devices 130 to perform operations suchas reading data, writing data, or erasing data at the memory devices 130and other such operations. The memory sub-system controller 115 caninclude hardware such as one or more integrated circuits and/or discretecomponents, a buffer memory, or a combination thereof. The hardware caninclude a digital circuitry with dedicated (i.e., hard-coded) logic toperform the operations described herein. The memory sub-systemcontroller 115 can be a microcontroller, special purpose logic circuitry(e.g., a field programmable gate array (FPGA), an application specificintegrated circuit (ASIC), etc.), or other suitable processor.

The memory sub-system controller 115 can include a processor 117 (e.g.,processing device) configured to execute instructions stored in a localmemory 119. In the illustrated example, the local memory 119 of thememory sub-system controller 115 includes an embedded memory configuredto store instructions for performing various processes, operations,logic flows, and routines that control operation of the memorysub-system 110, including handling communications between the memorysub-system 110 and the host system 120.

In some embodiments, the local memory 119 can include memory registersstoring memory pointers, fetched data, etc. The local memory 119 canalso include read-only memory (ROM) for storing micro-code. While theexample memory sub-system 110 in FIG. 1 has been illustrated asincluding the memory sub-system controller 115, in another embodiment ofthe present disclosure, a memory sub-system 110 does not include amemory sub-system controller 115, and can instead rely upon externalcontrol (e.g., provided by an external host, or by a processor orcontroller separate from the memory sub-system).

In general, the memory sub-system controller 115 can receive commands oroperations from the host system 120 and can convert the commands oroperations into instructions or appropriate commands to achieve thedesired access to the memory devices 130. The memory sub-systemcontroller 115 can be responsible for other operations such as wearleveling operations, garbage collection operations, error detection anderror-correcting code (ECC) operations, encryption operations, cachingoperations, and address translations between a logical address (e.g.,logical block address (LBA), namespace) and a physical address (e.g.,physical MU address, physical block address) that are associated withthe memory devices 130. The memory sub-system controller 115 can furtherinclude host interface circuitry to communicate with the host system 120via the physical host interface. The host interface circuitry canconvert the commands received from the host system into commandinstructions to access the memory devices 130 as well as convertresponses associated with the memory devices 130 into information forthe host system 120.

The memory sub-system 110 can also include additional circuitry orcomponents that are not illustrated. In some embodiments, the memorysub-system 110 can include a cache or buffer (e.g., DRAM) and addresscircuitry (e.g., a row decoder and a column decoder) that can receive anaddress from the memory sub-system controller 115 and decode the addressto access the memory devices 130.

In some embodiments, the memory devices 130 include local mediacontrollers 135 that operate in conjunction with memory sub-systemcontroller 115 to execute operations on one or more memory cells of thememory devices 130. An external controller (e.g., memory sub-systemcontroller 115) can externally manage the memory device 130 (e.g.,perform media management operations on the memory device 130). In someembodiments, a memory device 130 is a managed memory device, which is araw memory device combined with a local controller (e.g., localcontroller 135) for media management within the same memory devicepackage. An example of a managed memory device is a managed NAND (MNAND)device.

The memory sub-system 110 includes a delay handling component 113 thatcan cause a delay between write operations of adjacent memory cells. Insome embodiments, the memory sub-system controller 115 includes at leasta portion of the delay handling component 113. For example, the memorysub-system controller 115 can include a processor 117 (processingdevice) configured to execute instructions stored in local memory 119for performing the operations described herein. In some embodiments, thedelay handling component 113 is part of the host system 110, anapplication, or an operating system.

The delay handling component 113 can be used to perform write operationsin adjacent cells with a delay. The write operations can be performedsuch that data is written to adjacent memory cells with at least aminimum delay. In an example, controller 115 can perform a first writeoperation to write a first portion of a set of host data on a first cellof a data block. The delay handling component 113 can monitor an elapsedtime since the first write operation is performed to determine whetherthe elapsed time satisfies a time condition. For example, a timecondition can be satisfied if the elapsed time is greater than athreshold time. If it is determined that the time condition is notsatisfied (e.g., the elapsed time is less than or equal to the thresholdtime), then the controller can perform a second write operation to writea second portion of the set of host data on a second cell of the datablock that is not adjacent to the first cell. The delay handlingcomponent 113 can continue to monitor the elapsed time since the firstwrite operation, and until the time condition is satisfied, controller115 can continue to write to a cell that is not adjacent to the firstcell. When it is determined that the time condition is satisfied (e.g.the elapsed time is greater than the threshold time), the controller 115can write the date to a cell that is adjacent to the first cell.Accordingly, delay handling component 113 causes the write operationsbetween adjacent first and second cells to have a delay. Further detailswith regards to the operations of the delay handling component 113 aredescribed below.

FIGS. 2A-2B depict an example of performing write operations in adjacentcells of a memory device 200 with a delay in response to a host request,in accordance with some embodiments of the present disclosure. Memorydevice 200 includes word lines 205 a-f and bit lines 210 a-f. Memorycells, such as memory cells at location 220 a-220 z, and 230 a-230 z,are located at the intersection of each of word lines 205 a-f and bitlines 210 a-f.

When a write operation is performed on a particular memory cell (e.g.,an aggressor cell), write disturb stress can affect data stored atmemory cells that are adjacent (e.g., victim cells) to the memory cellthat the write operation was performed on. Adjacent cells can includecells that are proximate, nearby, neighboring, contiguous, etc., to eachother. The further away a memory cell is from another memory cell, thelesser is the effect of write disturb stress on each other. In anexample, if a write operation is performed on memory cell at location220 d, then write disturb can have the highest effect on data stored atmemory cells at locations 230 a, 230 e, 230 g, and 230 d which are alladjacent to location 220 d. As the distance between the cells increase,the effect of write disturb gets reduced. Thus, write disturb effectfrom location 220 d is minimized at locations that are not adjacent tolocation 220 d, such as, locations 220 a, 220 b, 230 b, 220 g, 220 h,220 e, 220 j, 230 b, etc. Additionally, while in some examples, anadjacent cell can include a cell immediately next to the aggressor cell,in other examples, an adjacent cell can include a cell that is not theimmediately next to the aggressor cell. Whether a cell is considered anadjacent cell can depend on the specific technological implementation ofthe memory sub-system and dimension of the array layout. For example, ifcells are placed relatively close to each other, then the range of cellsthat are considered victim cells to the write operation in an aggressorcell can widen and will include more devices. For example, in someconfiguration of the memory sub-system, cells 220 a, 220 b, 220 g, 220 hwhich are diagonal cells to 220 d can be impacted by the write operationin cell 220 d due to the placement of the cells being in close proximityto cell 220 d. In that case, the diagonal cells can be considered to beadjacent cells to the aggressor cell. Moreover, as time passes afterperforming a write operation on a particular memory cell, the heatgenerated from the write operation is dissipated and after a certainamount of time elapses since the write operation is performed, theeffect of write disturb is minimized on a cell adjacent to theparticular cell. For example, if a write operation is performed onmemory cell at location 220 d at time t1, the effect of write disturbfrom data written on location 220 d is minimized on adjacent location230 a, 230 e, 230 g, and 230 d after a certain amount of time delayafter time t1. A delay can be a lag, gap, or wait time between twooperations. The time sufficient to minimize the write disturb effect onan adjacent cell can vary based on specification of the memorysub-system.

In an embodiment of the present disclosure, the memory sub-system canreceive a request to write a set of host data and can perform writeoperations to write the set of host data to memory cells of memorydevice 200. To mitigate the effects of write disturb caused by a writeoperation performed on a particular memory cell on its adjacent cells,the memory sub-system performs write operations such that time elapsedbetween writing to adjacent cells satisfies a threshold time sufficientto overcome the write disturb effect of performing a write operation onthe adjacent cells, without increasing the overall time to write datafor a host request. For example, if a write operation is performed onmemory cell at location 220 d, the memory sub-system performs thesubsequent write operation to a location that is not adjacent tolocation 220 d. That is, the memory sub-system skips performing thesubsequent write operation at any of the memory cells located at 230 a,230 e, 230 g, and 230 d and performs the write operation to anothermemory cell location besides locations 230 a, 230 e, 230 g, and 230 d.The memory sub-system then performs a write operation to one of thecells located at 230 a, 230 e, 230 g, and 230 d after a minimum timedelay (e.g., a threshold time defined within the memory sub-system) haspassed since the write operation was performed at memory cell location220 d. In this manner, no wait time is experiences between consecutivewrite operations performed by the memory sub-system, while a delay isinherently introduced for write operations between adjacent cells, andoverall time to perform the write operations for the host system is notincreased compared to performing consecutive write operations inadjacent cells.

In some implementations, the memory sub-system can use a particularpattern of write operations such that data is written to locations wherethe write disturb effect of performing write operations on particularcells is minimized during the time the write disturb effect stillexists. The memory sub-system can use another pattern of writeoperations to write the remaining data to the remaining cells in thememory device 200 that are adjacent to the particular cells at a timeafter a sufficient time delay has passed for the write disturb effect tohave minimized.

In an embodiment, the memory sub-system can receive a request to write aset of host data and can perform a plurality of write operations towrite the set of host data to memory cells of memory device 200. Forexample, in one implementation, the memory sub-system can use a patternsimilar to a checkerboard pattern, where alternating locations are usedfor writing portions of the host data in consecutive write operations.As shown in FIG. 2A, the memory sub-system performs the plurality ofwrite operations following a first pattern using alternating memorycells. According to the first pattern, the memory sub-system starts thewrite operations using word line 205 a, and performs a first writeoperation of the plurality of write operations to write a first portionof the set of host data to a first memory cell located at a firstlocation 220 a. (e.g., at word line 205 a and bit line 210 a). Then thememory sub-system continues on word line 205 a, but bypasses the nextbit line 210 b to skip writing on memory cell 230 a, and performs asecond write operation of the plurality of write operations to write asecond portion of the set of host data to a second memory cell locatedat location 220 b. (e.g., at word line 205 a and bit line 210 c). Thememory sub-system continues to perform write operations on word line 205a, skipping the memory cells (e.g., 230 b, 230 c) at every other bitline, until no bit line on word line 205 a remains to be written to. Inthis manner, the memory sub-system performs a write operation in onecell and skips performing the subsequent write operation at the adjacentcell that is impacted by write disturb of the preceding write operationon the previous cell. The memory sub-system then continues to write onthe next word line 205 b. The memory sub-system skips writing on memorycell 230 d on bit line 210 a, since cell 230 d is located adjacent tocell 220 a where write operation has been performed. The memorysub-system performs the subsequent write operation of the plurality ofwrite operations on memory cell 220 d, and so on, skipping everyalternate memory cell (e.g., 230 e, 230 f, etc.) on word line 205 b. Thefirst pattern of the write operations can continue to be used for eachword line on memory device 200, avoiding writing in adjacent memorycells for consecutive write operations to finish writing the set of hostdata, minimizing write disturb.

In one implementation, the memory sub-system can monitor a time that haselapsed (“elapsed time”) since the first write operation is performed towrite the first portion of the set of host data at memory cell 220 a.The memory sub-system can determine whether the elapsed time satisfies atime condition. For example, the elapsed time can satisfy the timecondition if the elapsed time is greater than a threshold time. Thememory sub-system can define a threshold time (e.g., a minimum delaytime) based on a specification of the memory sub-system, such that thethreshold time is sufficient to minimize the write disturb effect of anaggressor cell on victim cells. If it is determined that the elapsedtime does not satisfy the time condition (e.g., the elapsed time isequal to or below the threshold time), then the memory sub-systemcontinues to perform rest of the plurality of write operations using thefirst pattern, writing portions of the host data in memory cells 220 b,220 c, 220 d, and so on, as described above with reference to FIG. 2A.The memory sub-system also continues to monitor the elapsed time todetermine whether the elapsed time satisfies the time condition afterperforming each write operation of the plurality of write operations.

In one implementation, if it is determined that the elapsed timesatisfies the time condition (e.g., elapsed time is greater thanthreshold time), the memory sub-system can cease to perform the rest ofthe write operations using the first pattern. For example, as depictedin FIG. 2A, after writing to memory cell 220 m of word line 205 e, thememory sub-system determines that the elapsed time is greater than thethreshold time, and stops performing subsequent write operations in wordline 205 e using the first pattern. Instead, upon determining the timecondition is satisfied, the memory sub-system can switch to using asecond pattern (e.g., an inverse checker board pattern), where thememory sub-system writes the remaining portions of the host data at thelocations adjacent to the aggressor cells that were previously skipped.For example, as depicted in FIG. 2B, the memory sub-system performs awrite operation to write a portion of the set of host data on memorycell 230 a, which is adjacent to the first location 220 a on which thefirst write operation was performed. The elapsed time between the writeoperation on location 220 a and the write operation on adjacent cell atlocation 230 a satisfies the time condition, as the elapsed time isgreater than the threshold time (e.g., the minimum delay time). As aresult, the effect of write disturb from the write operation on theaggressor cell located at 220 a is minimized on the adjacent celllocated at 230 a by the time the data is written on the adjacent cell at130 a. The memory sub-system continues to write the remaining portionsof the set of host data in the remaining memory cells 230 b, 230 c, 230d, and so on (e.g., the cells which were skipped during performing thewrite operations using the first pattern), until the remaining of thehost data is written in memory device 200, finishing the writeoperations at memory cell 230 g.

In one implementation, even if it is determined that the elapsed timesatisfies the time condition (e.g., elapsed time is greater thanthreshold time), the memory sub-system can nevertheless continue toperform the write operations using the first pattern. For example, thememory sub-system can continue to write the data at memory cell 220 n,after skipping memory cell at the intersection of bit line 210 b on wordline 205 d. The memory sub-system can continue to write the data untildata is written at the last memory cell 220 z on the last word line 205f. In some implementation, continuing to write data until the end of theword line can guarantee that the elapsed time is greater than thethreshold time due to the specification of the memory sub-system. Insuch cases, the memory sub-system can perform the write operations usingthe first pattern until the end of the word line is reached, withoutmonitoring the elapsed time to determine whether the time condition issatisfied, because by default the elapsed time is known to be greaterthan the threshold time in such memory sub-systems by the time end ofthe word line is reached. At that time, the memory sub-system can switchto performing the write operations using the second pattern as shown inFIG. 2B, in which case memory sub-system writes data in memory cell 230a adjacent to the first memory cell 220 a, and the elapsed time betweenthe write operations in the two adjacent cells are greater than thethreshold time by design.

In an implementation, if elapsed time is not satisfied when the wordline ends due to the particular specification of the memory sub-system,the memory sub-system does not switch to writing the data using thesecond pattern as shown in FIG. 2B, as the effect of write disturb isnot minimized on the adjacent cells yet. In such cases, the memorysub-system can perform the subsequent write operations on a differentdata unit, such as on a different block, plane, or memory device. In animplementation, when the memory sub-system performs write operationsusing the second pattern and the end of the last word line is reached(e.g., all memory cells have been used) before finishing writing thehost data fully, the memory sub-system can write the host data toanother data unit (e.g., different block, plane, or memory device, etc.)following the patterns described in FIGS. 2A and 2B.

In some implementations, the memory sub-system tracks an individualelapsed time for each of the write operations of the plurality of writeoperations on aggressor cells and determines whether each of theindividual elapsed time satisfies the time condition and then writesdata to each of the adjacent cells to the aggressor cells based on thedetermination that each of the respective individual elapsed timesatisfies the time condition.

In some implementations, the patterns used by the memory sub-system arepredefined within the memory sub-system. The memory sub-system canidentify available locations corresponding to memory cells to which datais to be written following a particular pattern. For example, for thefirst pattern described in FIG. 2A, the memory sub-system can identifymemory cells 220 a, 220 b, 220 c through 220 z as available memory cellsfor use with the first pattern. That is, after the memory sub-systemfinishes writing data to cell 220 a, the next memory cell available forperforming the subsequent write operation is identified as 220 b, and soon. Similarly, for the second pattern shown in FIG. 2B, the memorysub-system can identify memory cells 230 a, 230 b, 230 c through 230 zas available memory cells for use with the second pattern. The order ofthe memory cells can be identified in the predefined list of memorycells available for use by the memory sub-system. The predefined listcan be stored in metadata.

In some implementations, the memory sub-system performs the writeoperations by tracking the memory cells that have been written to andthe memory cells that remain to be written to. For example, the memorysub-system can track that a write operation was performed using memorycell 220 a. The memory sub-system can dynamically determine to skip theadjacent memory cell 230 a by skipping to write data in the next bitline 210 b. The memory sub-system can detect which cells are adjacent tocell 220 a and keep track of the adjacent cells. For the subsequentwrite operation, the memory sub-system skips writing the data in theidentified adjacent cells. Skipping decision by the memory sub-systemcan be made based on a previously defined and loaded information and/orlogic in the system (e.g., including, but not be limited to, part of thedelay handling component 113). The memory sub-system skips writing tothe adjacent cells if the elapsed time between the writes is equal to orbelow a predefined threshold value. The predefined threshold value canalso be stored as part of the delay handling component 113. Thisinformation is defined per technology node, and is pre-programmed in thesystem.

FIGS. 3A-3B depict an example of performing write operations in memorycells of memory device 300 from multiple host requests, in accordancewith some embodiments of the present disclosure. A host system (e.g.,host system 120 in FIG. 1) can initiate a data operation (e.g., write,read, erase, etc.) on a memory sub-system (e.g., memory sub-system 110in FIG. 1). The host system can send access requests (e.g., writecommand, read command) to the memory sub-system, such as to store dataon a memory device at the memory sub-system and to read data from thememory device on the memory sub-system. The data to be read or written,as specified by a host request, is hereinafter referred to as “hostdata”. A host request can include logical address information (e.g.,logical block address (LBA), namespace) for the host data, which is thelocation the host system associates with the host data. The logicaladdress information (e.g., LBA, namespace) can be part of metadata forthe host data.

In an embodiment, the memory sub-system can receive a first request towrite a first set of host data (“first data set”) and a second requestto write a second set of host data (“second data set”). The memorysub-system can perform write operations to write the first set of hostdata and the second set of host data on memory device 300, such that theelapsed time between write operations on aggressor cell and victim celladjacent to the aggressor cell satisfies a time condition (e.g., greaterthan a threshold time).

In one implementation, it is determined that an elapsed time betweenperforming a first write operation for the first data set and a firstwrite operation for the second data set satisfies the time condition. Inone example, the time condition can be satisfied due to the first set ofdata including a large amount of data that takes longer than thethreshold time to write. In another example, the time condition can besatisfied because the second request is received after the thresholdtime has passed since the first write operation for the first data set.When the elapsed time satisfies the time condition, the memorysub-system can continue to perform the first operation of the seconddata set using the first pattern as described in FIG. 2A. Alternatively,the memory sub-system can switch to writing the second set of data usingthe second pattern as described in FIG. 2B.

In one example, as shown in FIG. 3A, the memory sub-system receives thefirst data set and performs write operations to write the first data setusing the first pattern in memory cells 320 a through 320 n. After thelast portion of the first data set is written to cell 320 n, it isdetermined that the elapsed time had satisfied the time condition. Thememory sub-system then receives the second data set and continues toperform write operations to write the second data set using the firstpattern in memory cells 320 o, 320 p, etc. (e.g., continuing to skipalternate cells). When the end of the word line 305 f is reached (e.g.,data written in cell 320 z), the memory sub-system can switch to performthe remaining write operations using the second pattern as described inFIG. 2B. In doing so, the elapsed time between write operations onadjacent cells 320 a and 330 a satisfies the time condition.

In another example, instead of continuing to perform the writeoperations for the second data set using the first pattern and writingin cell 320 o, upon determining that the elapsed time satisfies the timecondition, the memory sub-system can switch to the second pattern (e.g.,inverse pattern) and write the second set of data starting in cell 330a, and continue to write in cell 330 b, 330 c, etc., as depicted in FIG.3B. In doing so, the elapsed time between write operations on adjacentcells 320 a and 330 a satisfies the time condition.

In one implementation, it is determined that an elapsed time betweenperforming a first write operation for the first data set and a firstwrite operation for the second data set does not satisfy the timecondition (e.g., elapsed time is equal to or less than the thresholdtime). For example, the first data set received at a time t1 can includea small amount of data that can be fully written in memory cell 320 a attime t2. The second data set can be received at time t3, where elapsedtime between time t2 and time t3 is less than the threshold time. Assuch, the memory sub-system continues to perform the write operationsfor the second data set using the first pattern in memory cells 320 b,320 c, and so on, such that write operations for the second data set arenot performed on adjacent data cells. Once it is determined that theelapsed time since the write operation on cell 320 a satisfies thethreshold time, the memory sub-system can continue to write theremaining data using the first pattern in memory cell 320 o, 320 p etc.Alternatively the memory sub-system can switch to the second patternafter the elapsed time satisfies the time condition, writing theremaining of the second data set to memory cells 330 a, 330 b, 330 c,and so on. In doing so, the elapsed time between write operations onadjacent cells 320 a and 330 a satisfies the time condition.

In some implementation, different patterns other than the checkerboardand inverse checkerboard patterns are used to perform the writeoperations. For example, instead of skipping one memory cell that isadjacent to the aggressor cell, the memory sub-system can skip two, ormore, memory cells after writing the data in the aggressor cell, andcontinue the pattern. Various other patterns can be used which canresult in the memory sub-system to perform consecutive write operationsin cells that are not adjacent to each other while performing writeoperations in adjacent cells with an elapsed time that meets a timecondition. Even though concepts in FIGS. 2A-2B and FIGS. 3A-3B has beendescribed using particular patterns, the patterns that can be used bythe memory sub-system to achieve write operations in adjacent cells witha delay is not limited to the particular patterns.

FIG. 4 is a flow diagram of an example method 400 to perform writeoperations in adjacent cells with a delay, in accordance with someembodiments of the present disclosure. The method 400 can be performedby processing logic that can include hardware (e.g., processing device,circuitry, dedicated logic, programmable logic, microcode, hardware of adevice, integrated circuit, etc.), software (e.g., instructions run orexecuted on a processing device), or a combination thereof. In someembodiments, the method 400 is performed by the delay handling component113 of FIG. 1. Although shown in a particular sequence or order, unlessotherwise specified, the order of the processes can be modified. Thus,the illustrated embodiments should be understood only as examples, andthe illustrated processes can be performed in a different order, andsome processes can be performed in parallel. Additionally, one or moreprocesses can be omitted in various embodiments. Thus, not all processesare required in every embodiment. Other process flows are possible.

At operation 410, the processing logic receives a request to write a setof host data. In some examples, the processing logic can receive a firstrequest to write a first set of host data and a second request to writea second set of host data. At operation 420, the processing logicperforms write operations to write a first portion of the set of hostdata to a first set of memory cells of the memory device arranged in afirst pattern. The first set of memory cells arranged in the firstpattern includes alternating memory cells on each word line of thememory device and excludes a second set of memory cells adjacent to thefirst set of memory cells. In an example, the write operations areconsecutive write operations.

At operation 430, the processing logic performs a second plurality ofwrite operations to write a second portion of the set of host data tothe second set of memory cells arranged in a second pattern. The secondset of memory cells arranged in the second pattern includes otheralternating memory cells on each word line of the memory device adjacentto the first set of memory cells. In an example, each of the second setof memory cells can be adjacent to each of the first set of memorycells. In some examples, performing the first plurality of writeoperations to the first set of memory cells arranged in the firstpattern and performing the second plurality of write operations to thesecond set of memory cells arranged in the second pattern causes anelapsed time between writing to adjacent cells of the memory device tosatisfy a time condition. In an example, the elapsed time satisfies thetime condition when the elapsed time is greater than a threshold time.In an example, the proceeding logic performs the second plurality ofwrite operations to the second set of memory cells arranged in thesecond pattern causes one of the alternating memory cells in the firstset of memory cells arranged in the first pattern to be adjacent to acorresponding one of the other alternating memory cells in the secondset of memory cells arranged in the second pattern. In some examples,the first pattern and the second pattern are predefined patterns thatidentify available memory cells for performing the first plurality ofwrite operations and the second plurality of write operations,respectively.

FIG. 5 is a flow diagram of an example method 500 for performing writeoperations using a time condition, in accordance with some embodimentsof the present disclosure. The method 500 can be performed by processinglogic that can include hardware (e.g., processing device, circuitry,dedicated logic, programmable logic, microcode, hardware of a device,integrated circuit, etc.), software (e.g., instructions run or executedon a processing device), or a combination thereof. In some embodiments,the method 400 is performed by the delay handling component 113 ofFIG. 1. Although shown in a particular sequence or order, unlessotherwise specified, the order of the processes can be modified. Thus,the illustrated embodiments should be understood only as examples, andthe illustrated processes can be performed in a different order, andsome processes can be performed in parallel. Additionally, one or moreprocesses can be omitted in various embodiments. Thus, not all processesare required in every embodiment. Other process flows are possible.

At operation 510, the processing logic performs a first write operationto write a first portion of a set of host data on a first location ofthe memory device. In an example, the first location corresponds to afirst memory cell of the memory device. The memory cell can be locatedat the intersection of a word line and a bit line.

At operation 520, the processing logic monitors an elapsed time sincethe first write operation is performed to determine whether the elapsedtime satisfies a time condition. In an example, the elapsed timesatisfies the time condition when the elapsed time is greater than athreshold time, and the elapsed time does not satisfy the time conditionwhen the elapsed time is equal to or less than the threshold time.

At operation 530, the processing logic, responsive to determining thatthe elapsed time does not satisfy the time condition, performs a secondwrite operation to write a second portion of the set of host data on asecond location of the memory device, wherein the second location is notadjacent to the first location. In an example, the first write operationand the second write operation are performed according to a firstpattern that causes the first location to be not adjacent to the secondlocation. In some examples, the first pattern is a predefined patternthat identifies available locations for performing write operations.Additionally, the processing logic continues to monitor the elapsed timeto determine whether the elapsed time satisfies the time condition.

At operation 540, the processing logic, responsive to determining thatthe elapsed time satisfies the time condition, performs a third writeoperation to write a third portion of the set of host data on a thirdlocation of the memory device, wherein the third location is adjacent tothe first location. Additionally, subsequent to performing the thirdwrite operation, the processing logic performs a fourth write operationto write a fourth portion of the set of host data on a fourth locationof the memory device, where the fourth location is adjacent to thesecond location. In an example, the second write operation and thefourth write operation are performed according to a second pattern thatcauses the third location to be adjacent to the first location and thefourth location to be adjacent to the second location.

Furthermore, responsive to determining that the elapsed time satisfiesthe time condition and prior to performing the third write operation,the processing logic performs a fifth write operation to write a fifthportion of the set of host data on a fifth location of the memorydevice, wherein the fifth location is not adjacent to the first locationor the second location.

FIG. 6 illustrates an example machine of a computer system 600 withinwhich a set of instructions, for causing the machine to perform any oneor more of the methodologies discussed herein, can be executed. In someembodiments, the computer system 600 can correspond to a host system(e.g., the host system 120 of FIG. 1) that includes, is coupled to, orutilizes a memory sub-system (e.g., the memory sub-system 110 of FIG. 1)or can be used to perform the operations of a controller (e.g., toexecute an operating system to perform operations corresponding to thedelay handling component 113 of FIG. 1). In alternative embodiments, themachine can be connected (e.g., networked) to other machines in a LAN,an intranet, an extranet, and/or the Internet. The machine can operatein the capacity of a server or a client machine in client-server networkenvironment, as a peer machine in a peer-to-peer (or distributed)network environment, or as a server or a client machine in a cloudcomputing infrastructure or environment.

The machine can be a personal computer (PC), a tablet PC, a set-top box(STB), a Personal Digital Assistant (PDA), a cellular telephone, a webappliance, a server, a network router, a switch or bridge, or anymachine capable of executing a set of instructions (sequential orotherwise) that specify actions to be taken by that machine. Further,while a single machine is illustrated, the term “machine” shall also betaken to include any collection of machines that individually or jointlyexecute a set (or multiple sets) of instructions to perform any one ormore of the methodologies discussed herein.

The example computer system 600 includes a processing device 602, a mainmemory 604 (e.g., read-only memory (ROM), flash memory, dynamic randomaccess memory (DRAM) such as synchronous DRAM (SDRAM) or RDRAM, etc.), astatic memory 606 (e.g., flash memory, static random access memory(SRAM), etc.), and a data storage system 618, which communicate witheach other via a bus 630.

Processing device 602 represents one or more general-purpose processingdevices such as a microprocessor, a central processing unit, or thelike. More particularly, the processing device can be a complexinstruction set computing (CISC) microprocessor, reduced instruction setcomputing (RISC) microprocessor, very long instruction word (VLIW)microprocessor, or a processor implementing other instruction sets, orprocessors implementing a combination of instruction sets. Processingdevice 602 can also be one or more special-purpose processing devicessuch as an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA), a digital signal processor (DSP),network processor, or the like. The processing device 602 is configuredto execute instructions 626 for performing the operations and stepsdiscussed herein. The computer system 600 can further include a networkinterface device 608 to communicate over the network 620.

The data storage system 618 can include a machine-readable storagemedium 624 (also known as a computer-readable medium) on which is storedone or more sets of instructions 626 or software embodying any one ormore of the methodologies or functions described herein. Theinstructions 626 can also reside, completely or at least partially,within the main memory 604 and/or within the processing device 602during execution thereof by the computer system 600, the main memory 604and the processing device 602 also constituting machine-readable storagemedia. The machine-readable storage medium 624, data storage system 618,and/or main memory 604 can correspond to the memory sub-system 110 ofFIG. 1.

In one embodiment, the instructions 626 include instructions toimplement functionality corresponding to a delay handling component(e.g., the delay handling component 113 of FIG. 1). While themachine-readable storage medium 624 is shown in an example embodiment tobe a single medium, the term “machine-readable storage medium” should betaken to include a single medium or multiple media that store the one ormore sets of instructions. The term “machine-readable storage medium”shall also be taken to include any medium that is capable of storing orencoding a set of instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresent disclosure. The term “machine-readable storage medium” shallaccordingly be taken to include, but not be limited to, solid-statememories, optical media, and magnetic media.

Some portions of the preceding detailed descriptions have been presentedin terms of algorithms and symbolic representations of operations ondata bits within a computer memory. These algorithmic descriptions andrepresentations are the ways used by those skilled in the dataprocessing arts to most effectively convey the substance of their workto others skilled in the art. An algorithm is here, and generally,conceived to be a self-consistent sequence of operations leading to adesired result. The operations are those requiring physicalmanipulations of physical quantities. Usually, though not necessarily,these quantities take the form of electrical or magnetic signals capableof being stored, combined, compared, and otherwise manipulated. It hasproven convenient at times, principally for reasons of common usage, torefer to these signals as bits, values, elements, symbols, characters,terms, numbers, or the like.

It should be borne in mind, however, that all of these and similar termsare to be associated with the appropriate physical quantities and aremerely convenient labels applied to these quantities. The presentdisclosure can refer to the action and processes of a computer system,or similar electronic computing device, that manipulates and transformsdata represented as physical (electronic) quantities within the computersystem's registers and memories into other data similarly represented asphysical quantities within the computer system memories or registers orother such information storage systems.

The present disclosure also relates to an apparatus for performing theoperations herein. This apparatus can be specially constructed for theintended purposes, or it can include a general purpose computerselectively activated or reconfigured by a computer program stored inthe computer. Such a computer program can be stored in a computerreadable storage medium, such as, but not limited to, any type of diskincluding floppy disks, optical disks, CD-ROMs, and magnetic-opticaldisks, read-only memories (ROMs), random access memories (RAMs), EPROMs,EEPROMs, magnetic or optical cards, or any type of media suitable forstoring electronic instructions, each coupled to a computer system bus.

The algorithms and displays presented herein are not inherently relatedto any particular computer or other apparatus. Various general purposesystems can be used with programs in accordance with the teachingsherein, or it can prove convenient to construct a more specializedapparatus to perform the method. The structure for a variety of thesesystems will appear as set forth in the description below. In addition,the present disclosure is not described with reference to any particularprogramming language. It will be appreciated that a variety ofprogramming languages can be used to implement the teachings of thedisclosure as described herein.

The present disclosure can be provided as a computer program product, orsoftware, that can include a machine-readable medium having storedthereon instructions, which can be used to program a computer system (orother electronic devices) to perform a process according to the presentdisclosure. A machine-readable medium includes any mechanism for storinginformation in a form readable by a machine (e.g., a computer). In someembodiments, a machine-readable (e.g., computer-readable) mediumincludes a machine (e.g., a computer) readable storage medium such as aread only memory (“ROM”), random access memory (“RAM”), magnetic diskstorage media, optical storage media, flash memory components, etc.

In the foregoing specification, embodiments of the disclosure have beendescribed with reference to specific example embodiments thereof. Itwill be evident that various modifications can be made thereto withoutdeparting from the broader spirit and scope of embodiments of thedisclosure as set forth in the following claims. The specification anddrawings are, accordingly, to be regarded in an illustrative senserather than a restrictive sense.

What is claimed is:
 1. A system comprising: a memory device; and aprocessing device, operatively coupled with the memory device, toperform operations comprising: receiving a request to write a set ofhost data; performing a first plurality of write operations to write afirst portion of the set of host data to a first set of memory cells ofthe memory device arranged in a first pattern, wherein the first patterncomprises a first plurality of alternating memory cells on each wordline of the memory device and excludes a second set of memory cells ofthe memory device adjacent to the first set of memory cells; andperforming a second plurality of write operations to write a secondportion of the set of host data to the second set of memory cellsarranged in a second pattern, wherein the second pattern comprises asecond plurality of alternating memory cells on each word line of thememory device adjacent to the first set of memory cells.
 2. The systemof claim 1, wherein the first plurality of write operations comprisesconsecutive write operations.
 3. The system of claim 1, whereinperforming the first plurality of write operations to the first set ofmemory cells arranged in the first pattern and performing the secondplurality of write operations to the second set of memory cells arrangedin the second pattern causes an elapsed time between writing to adjacentcells of the memory device to satisfy a time condition.
 4. The system ofclaim 1, wherein the first pattern and the second pattern are predefinedpatterns that identify available memory cells for performing the firstplurality of write operations and the second plurality of writeoperations, respectively.
 5. The system of claim 3, wherein the elapsedtime satisfies the time condition when the elapsed time is greater thana threshold time.
 6. The system of claim 1, wherein performing thesecond plurality of write operations to the second set of memory cellsarranged in the second pattern causes one of the alternating memorycells in the first set of memory cells arranged in the first pattern tobe adjacent to a corresponding one of the other alternating memory cellsin the second set of memory cells arranged in the second pattern.
 7. Amethod comprising: performing a first write operation to write a firstportion of a set of host data to a first location of the memory device;monitoring an elapsed time since the first write operation is performedto determine whether the elapsed time satisfies a time condition;responsive to determining that the elapsed time does not satisfy thetime condition: performing, by a processing device, a second writeoperation to write a second portion of the set of host data to a secondlocation of the memory device, wherein the second location is notadjacent to the first location; and continuing to monitor the elapsedtime to determine whether the elapsed time satisfies the time condition;and responsive to determining that the elapsed time satisfies the timecondition, performing a third write operation to write a third portionof the set of host data to a third location of the memory device,wherein the third location is adjacent to the first location.
 8. Themethod of claim 7, wherein the elapsed time satisfies the time conditionwhen the elapsed time is greater than a threshold time, and wherein theelapsed time does not satisfy the time condition when the elapsed timeis equal to or less than the threshold time.
 9. The method of claim 7,further comprising: subsequent to performing the third write operation,performing a fourth write operation to write a fourth portion of the setof host data on a fourth location of the memory device, wherein thefourth location is adjacent to the second location.
 10. The method ofclaim 7, wherein the first write operation and the second writeoperation are performed according to a first pattern that causes thefirst location to be not adjacent to the second location.
 11. The methodof claim 10, wherein the first pattern is a predefined pattern thatidentifies available locations for performing write operations.
 12. Themethod of claim 9, wherein the second write operation and the fourthwrite operation are performed according to a second pattern that causesthe third location to be adjacent to the first location and the fourthlocation to be adjacent to the second location.
 13. The method of claim7, further comprising: responsive to determining that the elapsed timesatisfies the time condition and prior to performing the third writeoperation, performing a fifth write operation to write a fifth portionof the set of host data on a fifth location of the memory device,wherein the fifth location is not adjacent to the first location or thesecond location.
 14. A non-transitory computer-readable storage mediumcomprising instructions that, when executed by a processing device,cause the processing device to: perform a first write operation to writea first portion of a set of host data on a first location of the memorydevice; monitor an elapsed time since the first write operation isperformed to determine whether the elapsed time satisfies a timecondition; responsive to determining that the elapsed time does notsatisfy the time condition: perform a second write operation to write asecond portion of the set of host data on a second location of thememory device, wherein the second location is not adjacent to the firstlocation; and continue to monitor the elapsed time to determine whetherthe elapsed time satisfies the time condition; and responsive todetermining that the elapsed time satisfies the time condition, performa third write operation to write a third portion of the set of host dataon a third location of the memory device, wherein the third location isadjacent to the first location.
 15. The non-transitory computer-readablestorage medium of claim 14, wherein the elapsed time satisfies the timecondition when the elapsed time is greater than a threshold time, andwherein the elapsed time does not satisfy the time condition when theelapsed time is equal to or less than the threshold time.
 16. Thenon-transitory computer-readable storage medium of claim 14, wherein theprocessing device is further to: subsequent to performing the thirdwrite operation, perform a fourth write operation to write a fourthportion of the set of host data on a fourth location of the memorydevice, wherein the fourth location is adjacent to the second location.17. The non-transitory computer-readable storage medium of claim 14,wherein the first write operation and the second write operation areperformed according to a first pattern that causes the first location tobe not adjacent to the second location.
 18. The non-transitorycomputer-readable storage medium of claim 17, wherein the first patternis a predefined pattern that identifies available locations forperforming write operations.
 19. The non-transitory computer-readablestorage medium of claim 16, wherein the second write operation and thefourth write operation are performed according to a second pattern thatcauses the third location to be adjacent to the first location and thefourth location to be adjacent to the second location.
 20. Thenon-transitory computer-readable storage medium of claim 17, wherein theprocessing device is further to: responsive to determining that theelapsed time satisfies the time condition and prior to performing thethird write operation, perform a fifth write operation to write a fifthportion of the set of host data on a fifth location of the memorydevice, and wherein the fifth location is not adjacent to the firstlocation or the second location.